WHICH FINISHES ARE FOOD-SAFE?
The short answer is, all of them. Some finishes used to contain lead as a drier, but that was banned years ago. The key is to allow finishes to fully cure, which takes up to 30 days. There are essentially two types of finish: oil, which penetrates the wood, and film forming, which lies on top of the wood.
If your wooden bowl or cutting board gets rough treatment with knives and utensils, use an oil finish like tung, mineral, linseed, or even an edible oil, such as olive or walnut oil. Just refresh the finish as needed with another coat of oil. Film finishes develop cracks with heavy use. These cracks allow water to get into the wood but don’t allow easy escape, and refinishing involves sanding the whole piece back to bare wood. If your item isn’t used for cutting, a film finish is fine.